feat: mark custom layers as externals (#225)

* feat!: remove support for JavaScript bundles * feat: add layers as externals
netlify · Nov 24, 2022 · a68607b · a68607b
1 parent d8f45b1
commit a68607b
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Showing 8 changed files with 18 additions and 11 deletions.
diff --git a/deno/bundle.ts b/deno/bundle.ts
@@ -1,6 +1,6 @@
 import { writeStage2 } from './lib/stage2.ts'
 
 const [payload] = Deno.args
-const { basePath, destPath, functions, importMapURL } = JSON.parse(payload)
+const { basePath, destPath, externals, functions, importMapURL } = JSON.parse(payload)
 
-await writeStage2({ basePath, destPath, functions, importMapURL })
+await writeStage2({ basePath, destPath, externals, functions, importMapURL })
diff --git a/deno/lib/consts.ts b/deno/lib/consts.ts
@@ -1,4 +1,3 @@
-export const CUSTOM_LAYER_PREFIX = 'layer:'
 export const PUBLIC_SPECIFIER = 'netlify:edge'
 export const STAGE1_SPECIFIER = 'netlify:bootstrap-stage1'
 export const STAGE2_SPECIFIER = 'netlify:bootstrap-stage2'

diff --git a/deno/lib/stage2.ts b/deno/lib/stage2.ts
@@ -3,7 +3,7 @@ import { build, LoadResponse } from 'https://deno.land/x/eszip@v0.28.0/mod.ts'
 import * as path from 'https://deno.land/std@0.127.0/path/mod.ts'
 
 import type { InputFunction, WriteStage2Options } from '../../shared/stage2.ts'
-import { CUSTOM_LAYER_PREFIX, PUBLIC_SPECIFIER, STAGE2_SPECIFIER, virtualRoot } from './consts.ts'
+import { PUBLIC_SPECIFIER, STAGE2_SPECIFIER, virtualRoot } from './consts.ts'
 import { inlineModule, loadFromVirtualRoot, loadWithRetry } from './common.ts'
 
 interface FunctionReference {
@@ -62,15 +62,15 @@ const getVirtualPath = (basePath: string, filePath: string) => {
   return url
 }
 
-const stage2Loader = (basePath: string, functions: InputFunction[]) => {
+const stage2Loader = (basePath: string, functions: InputFunction[], externals: Set<string>) => {
   return async (specifier: string): Promise<LoadResponse | undefined> => {
     if (specifier === STAGE2_SPECIFIER) {
       const stage2Entry = getStage2Entry(basePath, functions)
 
       return inlineModule(specifier, stage2Entry)
     }
 
-    if (specifier === PUBLIC_SPECIFIER || specifier.startsWith(CUSTOM_LAYER_PREFIX)) {
+    if (specifier === PUBLIC_SPECIFIER || externals.has(specifier)) {
       return {
         kind: 'external',
         specifier,
@@ -85,8 +85,8 @@ const stage2Loader = (basePath: string, functions: InputFunction[]) => {
   }
 }
 
-const writeStage2 = async ({ basePath, destPath, functions, importMapURL }: WriteStage2Options) => {
-  const loader = stage2Loader(basePath, functions)
+const writeStage2 = async ({ basePath, destPath, externals, functions, importMapURL }: WriteStage2Options) => {
+  const loader = stage2Loader(basePath, functions, new Set(externals))
   const bytes = await build([STAGE2_SPECIFIER], loader, importMapURL)
   const directory = path.dirname(destPath)
 

diff --git a/node/bundler.test.ts b/node/bundler.test.ts
@@ -271,7 +271,7 @@ test('Processes a function that imports a custom layer', async () => {
       path: '/func1',
     },
   ]
-  const layer = { name: 'test', flag: 'edge-functions-layer-test' }
+  const layer = { name: 'layer:test', flag: 'edge-functions-layer-test' }
   const result = await bundle([sourceDirectory], tmpDir.path, declarations, {
     basePath: fixturesDir,
     configPath: join(sourceDirectory, 'config.json'),

diff --git a/node/bundler.ts b/node/bundler.ts
@@ -73,6 +73,9 @@ const bundle = async (
   // exists.
   const deployConfig = await loadDeployConfig(configPath, logger)
 
+  // Layers are marked as externals in the ESZIP, so that those specifiers are
+  // not actually included in the bundle.
+  const externals = deployConfig.layers.map((layer) => layer.name)
   const importMap = new ImportMap()
 
   if (deployConfig.importMap) {
@@ -86,9 +89,10 @@ const bundle = async (
     debug,
     deno,
     distDirectory,
+    externals,
     functions,
-    importMap,
     featureFlags,
+    importMap,
   })
 
   // The final file name of the bundles contains a SHA256 hash of the contents,

diff --git a/node/formats/eszip.ts b/node/formats/eszip.ts
@@ -17,6 +17,7 @@ interface BundleESZIPOptions {
   debug?: boolean
   deno: DenoBridge
   distDirectory: string
+  externals: string[]
   featureFlags: FeatureFlags
   functions: EdgeFunction[]
   importMap: ImportMap
@@ -28,6 +29,7 @@ const bundleESZIP = async ({
   debug,
   deno,
   distDirectory,
+  externals,
   functions,
   importMap,
 }: BundleESZIPOptions): Promise<Bundle> => {
@@ -37,6 +39,7 @@ const bundleESZIP = async ({
   const payload: WriteStage2Options = {
     basePath,
     destPath,
+    externals,
     functions,
     importMapURL: importMap.toDataURL(),
   }

diff --git a/shared/stage2.ts b/shared/stage2.ts
@@ -6,6 +6,7 @@ export interface InputFunction {
 export interface WriteStage2Options {
   basePath: string
   destPath: string
+  externals: string[]
   functions: InputFunction[]
   importMapURL?: string
 }
diff --git a/test/fixtures/with_layers/functions/config.json b/test/fixtures/with_layers/functions/config.json
@@ -1,4 +1,4 @@
 {
-  "layers": [{ "name": "test", "flag": "edge-functions-layer-test" }],
+  "layers": [{ "name": "layer:test", "flag": "edge-functions-layer-test" }],
   "version": 1
 }